Quantum Vacuum

Quantum mechanics tells us that there is no such thing as empty space. Even the most perfect vacuum is actually filled by a roiling cloud of particles and antiparticles, which flare into existence and almost instantaneously fade back into nothingness. These so-called virtual particles don’t last long enough to be observed directly, but we know they exist by their effects.

According to quantum physics, even vacuums are not completely empty. Constant fluctuations in energy can spontaneously create mass not just out of thin air, but out of absolutely nothing at all. … This peculiar nature of vacuum, sometimes referred to as “quantum vacuum,” is not just theoretical speculation.

According to quantum mechanics, the vacuum state is not truly empty but instead contains fleeting electromagnetic waves and particles that pop into and out of the quantum field.

Wikipedia

BBC